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(No Model.)

J. S. McOOY.

STEAM ENGINE. No. 343,385. Patented June 8, 1886.

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WITNESSES:

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UN TED STATES ATENT UFFICE.

JAMES S. MCCOY, OF BROOKLYN, NEW YORK.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 343.385, dated June 8,1836.

Application filed October 8. 1885. Serial No. 179,279. (No moth-l.)

To all whom it may concern: 7

Be it known that I, JAMES S. MCCOY, of Brooklyn, in the county of Kingsand State of New York, have invented a new and Improved Steam-Engine. ofwhich the following is a full, clear, and exact description.

My invention relates to a steam engine wherein the slide valve iscarried by and within the piston; and the invention consists,principally,of a steam-engine wherein a steamspace is formed around thepiston in the cylinder, so that the piston is rendered almost entirelyfrictionless in the cylinder by a surrounding packing or cushion ofsteam.

The invention also consists of the arrangement and relative size of thesteam inlet and exhaust ports with the space surrounding the piston,whereby proper retention of steam is effected for filling the spacearound thepiston, so as to prevent contact of the piston with thecylinder, and. also to prevent excessive upward pressure of steam on thepiston,to avoid I friction of the piston with the cylinder opposite theinduction-port.

The invention further consists in forming the steam-inlet port to thecylinder immediately below the piston, whereby the pressure of steamentering the port will counteract the weight of the piston and tend tolift it out of frictional contact with the inner lower wall of thecylinder.

' The invention finally consists of the piston carrying the slide-valveand attached rigidly to the piston-rod, and working in a cylinder havingsuit-able steam inlet and exhaust ports, combined with a crank-shaft andconnectingrod connecting the shaft with the piston-rod.

Reference is to be had to the accompanying drawings, forming part ofthis specification, in which similar letters of reference indicatecorresponding parts in all the figures.

Figure 1 is asectional elevation of my new and improved steam-engine.Figs. 2 and 3 are reverse views of the cylinder, the outer casing beingremoved. Fig. 4 is a sectional plan view on the line w w of Fig. 1. Fig.5 is a transverse sectional elevation of the cylinder and piston,takenon the line 3 y of Fig. l; and Figs. 6 and 7 are reverse views of theopposite ends of the piston.

A represents the cylinder; B, the piston, and G the valve, placed in atransverse chamber, B, made through the piston B. The piston B isattached rigidly to the piston-rod D, which passes through thecylinder-cap b and stnffing box c, and is connected to the crosshead E,which runs in ways F, and is corinected with the crank-shaft G by theconnectingrod H.

The cylinder A. is mounted on a support, I, and held firmly thereto bythe cap I, and is composed of the shell J and tube or outer casing, J,that surrounds the shell J, as shown clearly in Figs. 1, 4, and 5.

The shell J is formed with the main steaminlet port a andexhaust-passage b, and it is faced off at c, as shown in Figs. 3 and 5,and also at d d d on the opposite side, as shown in Figs. 2 and 5. p

In the flat surface 0 is formed the port 6, and the steam-inlet port aopens into the flat surface 0. The exhaust-passage b is the same size asthe inlet-port a, and opens out of the flat surface (I, and in the flatsurfaces (1 d are formed through the shell J the steam-passages ff. Fromthe flat surface a the casing J is grooved, as shown at g, and again onthe opposite side at g. The groove 9 leads to a port, it, made in theshell J, while the groove g on the opposite sideleads to the port h.From the Hat surfaces d d the shell J is grooved, as shown at z i. Thegroove '5 leads to the port j, while the groove 2" leads to the port 9',both ports shown in full linesin Fig. 4, and in dotted lines in Fig. 2.

The piston B is made of considerable length, and is of smaller diameterthan the interior of the shell J, so as to leave an appreciable space,8, between the outer surface of the piston and the inner wall of theshell, as shown in Fig. 5, so that when steam enters the shell J it willenvelop the piston B, occupying space 8, and completely cushion thepiston all about with steam, so that there is practically no friction ofthe piston with the steam-chest.

The valve 0 is of a. length nearly equal to the diameter of the pistonB, and the latter has the passages 70 formed in it, which reach throughto the chamber B in the piston that contains the valve 0, and theseopenings coincide with or stand in the same plane with the ports f f ofthe shell J, Figs. 2 and 5, and the piston also has the passage Z formedin it. (Shown in dotted lines in Fig. 4, and in full lines in Fig. 5.)The passage 6 also reaches I through to the valve-chamber 13, and itcoin cides with or stands in the same plane with the steanrinlet port 0,made in the shell J. The piston B also has the longitudinal passages ona formed in it, which reach, respectively, from the valve-chamberB tothe opposite ends of the piston, as shown in dotted lines in Fig. 4.,and in full lines in Figs. 6 and 7, and the piston is kept from turningaxially in the shell J by the pin or rib 0 in the shell entering theslot 0 made in the piston. The valve 0 is eireumferentially grooved at qq, so that the valve in its reciprocation in the valve-chambcr B, causedby steam -pressure entering the ports 71. h, alternately opens andcloses the steam ports or passages in the piston 13.

In horizontal engines the shell J will be set with the mainsteanrinletport 0 immediately below the piston 13, as shownin Fig. 1, sothat the pressure of steam entering the engine will impinge upon andlift the piston in the cylinder, and thus overcome the friction whichwould otherwise be due to the weight of the piston resting and movingupon the inner lower surface of the cylinder. This lifting of the pistonby steam-pressure also prevents uneven wear of the piston 13.

The operation of the engine is as follows: The piston 13 being in itsrearward position, steam admitted to the port a enters the passageformed by the flat surface 0, and passes through thepassage c, lifts andsurrounds the piston, and passes through groove 9 and port h, movingvalve 0 to close passage 7.2 and connect passages e, l, and m, thusadmitting steam back of the piston B, and at the same time opening orconnecting passages k, f, and a, to allow exhaust from in front of thepiston to and through the space formed by the flat surfaces (Z d and thepassage 1). Then the steam entering through the groove y and passage hmoves valve G to close passage 7., and to connect passages e Z a toadmit steam in front of the piston, and also to connect passages in 7.?f to open the exhaust from back of the piston, and so on alternatelycausing the piston B to have a reciprocating motion, causing it totransmit rotary motion to the crankshaft G. 15xhaust from thevalve'chamber B is permitted through the grooves and ports ij and i andj to the main exhaust (1 db, so there will be no back-pressure to impedethe movement of the valve, and the exhaust-port I) being of the samesize as the steam-inlet port a, the steam will be confined in the spaces sufficiently to support the piston and prevent friction, and theretarded exhaust, consequent upon the comparatively small exhaust-portb,causes the steam above the piston in the space a to connteraet theupward pressure of the steam on the piston and prevent it from beinglifted into contact with the cylinder.

Instead of using steam, compressed air or other gas may be used foroperating the englue.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

1. The piston 15, formed with steam-passages, as described, and carryinga transverselyarranged slide-valve, G, and made of smaller diameter thanthe interior of the steam-chest A, to form thespace 8 around the piston,in combination with the cylinder having steam inlet and exhaust portsformed at or near the center of the piston-stroke, whereby the piston issurrounded and cushioned with steam, substantially as and for thepurposes set forth.

2. In an engine, the exhaust-port I), Fig. 2, made of the same size asindnction-porta, Fig. 3, in combination with said induction-port (1, andthe several eduetion ports and channels, as described, for the purposeof properly tilling space 8 with steam, so as to prevent contact betweenthe piston and cylinder.

3. In an engine, the combination of the eduction-ports i iff b andcduclion-ehannels (Z d (7/, Fig. 2, in cylinder A, ofsnch size andposition in relation to imluction-ports a c gy in cylinder A as todetain the exhauststeam, so as to counteract the upward pressure of thesteam on the piston sulliciently to prevent friotional contact of thepiston and cylinder at the opposite side from the inductionport 0.

4. The piston 13, made smaller in diameter than the cylinder-bore toform the surround iug space 8, and provided with slide-valve (J,audt'ormed with ports controlled by the valve 0, to admit steam to andexhaust it from both ends of the cylinder, iucombination with thecylinder having medial exhaust-ports and the medial bottom steanriuletport, 8, whereby the pressure of steam entering the port 6 will lift thepiston in space 8 and prevent friction, substantially as described.

JAMES S. MoGOY.

\Vitnesses:

II. A. WEs'r, C. Snnowloir.

